L7 - Congenital Heart Disease I

Question 1

Give two examples of how you would acquire a congenital heart disease

Answer 1

Genetics - Down’s/Turner’s/Marfan’s
Environmental - teratogenecity from drugs/alcohol
Maternal infections - Rubella

Question 2

What is the prevalence of congenital heart disease in the general population?

Answer 2

1 in 100

Question 3

Which is more immediately dangerous and why?

a) a persistent left to right shunt after birth
b) a persistent right to left shunt after birth

Answer 3

B) - in this kind of shunt the lungs are bypassed completely by the circulation resulting in deoxygenated blood going to the body

Question 4

Which are acyonotic, left to right shunts or right to left shunts?

Answer 4

Left to right because they pass through the lungs

Question 5

Give two examples of left to right shunts

Answer 5

ASD - Atrial septal defect
VSD - Ventricular septal defect
PDA - Patent ductus arteriosus - explanation - between pulmonary artery and aorta. Pressure gradient move to PA -> round lungs - acyanotic left to right

Question 6

Give some examples of obstructive lesions that are acyanotic

Answer 6

Aortic stenosis/pulmonary stenosis/coarctation of the aorta/mitral stenosis

Explanation - none of these are affecting the oxygen saturation of haemoglobin but may result in ischaemia - I think this is right

Question 7

Give two examples of right to left shunts

Answer 7

Tetralogy of Fallot
Transposition of the great arteries
Total anomalous pulmonary venous drainage
Univentricular heart

Question 8

Right to left shunts are cyanotic. T/F?

Answer 8

T

Question 9

Give two haemodynamic effects you might see in a typical ASD, one is increased pulmonary blood flow

Answer 9

RV Volume overload
Possibly pulmonary hypertension (rare)
Eventual right heart failure

Question 10

Give the haemodynamic effects of a ventricular septal defect

Answer 10

LV Volume overload
Pulmonary venous congestion
Eventual pulmonary hypertension

Question 11

What kind of septal defect is most common in Down’s syndrome?

Answer 11

Atrio-ventricular septal defects (AVSDs)

Question 12

What is coarctation?

Answer 12

Narrowing of the aorta at the level of the ligament in arteriosum and a PDA

Question 13

Are the following pulses the same or weaker in coarctation of the aorta?

a) femoral
b) radial

Answer 13

a) weaker
b) unaffected

Explanation - coarctation doesn’t affect the subclavian arteries which branch into the radial ones

Question 14

What are the four factors in the Tetralogy of Fallot?

Answer 14

Pulmonary stenosis
VSD
Right ventricular hypertrophy
Overriding aorta

Question 15

What is the single cause of Tetralogy of Fallot?

Answer 15

Overrotation in development of the heart causes the outflow portion of the interventricular septum to sit too anterior

Explanation - basically results in a hole in the ventricle walls. So deoxygenated and oxygenated blood mix. The aorta arises above both ventricles meaning some deoxygenated blood can go to rest of body

Question 16

What is tricuspid atresia?

Answer 16

Lack of development of a tricuspid valve. Explanation - this leaves no inlet into the right ventricle. Now need a shunt to LA and one to the lungs - cyanotic

Question 17

Describe transposition of the great arteries and what is done to correct it

Answer 17

Aorta connected to the right ventricle and pulmonary artery connected to left ventricle (wrong way round compared to normal)

A bidirectional shunt (atrial/ventricular/ductal) is allowed to persist via prostaglandins and/or artificially put in. Then operation to put the vessels in correct place

Question 18

describe hypoplastic left heart congenitally?

Answer 18

Left ventricle is underdeveloped, ascending aorta is very small. Right ventricle instead supports the systemic circulation

For even short term survival there must be ASD (atrial septal defect) and PDA (patent ductus arteriosus) shunts - PDA connects the pulmonary artery to the aorta